114 Mr. H. J. Carter on the Development 
quence to remember here is the “ transparent granuliferous 
substance ”’ (“‘ sarcodine”’ and ‘‘ granula,” Hiickel), as this 
is the primordial element of the single ovicell or ovum from 
which by evolution all the rest is developed ; whilst the “ hard 
parts’ consist of the grey or colourless granular core 
(fig. 10, a), which may also contain foreign bodies or spicules 
developed by the sponge itself, according to the species, and 
of the horny lamine or kerasine (fig. 10,6), which together 
form the fibre. 
Now, if we examine microscopically the fibre of Luffaria, 
the axial structure will be found to consist of the granuliferous 
core just mentioned, which, being comparatively soft and 
colourless or of a light grey colour, contrasts strongly with 
the external part, which is horny, concentrically lamellated, 
and of a transparent brown or amber colour. Both these 
structures are sharply differentiated ; and in thin transverse 
sections the axial one becomes so separated from the horny 
cylinder that it may be picked out and easily examined under 
a high magnifying-power (say 450 diameters), when the 
granuliferous substance of which it is composed closely re- 
sembles the ‘“‘ granuliferous transparent substance ”’ of the sar- 
code, while the granules, which are yellowish and opaque, 
appear to be spherical (? cellule in embryo), and become, 
when dyed with red aniline, much deeper in colour than the 
EStn le gIPNO etree lala) e 
Thus the question arises whether the horny layers of the 
fibre are formed by successive additions to its interior through 
the granuliferous substance, or whether they are supplied by 
the sarcode or parenchyma externally. 
If we follow the axial substance of the interior, say in the 
Psammonemata, where the fibre for the most part 1s cored 
with foreign bodies, it will be found that the axial substance 
encloses these bodies, which, indeed, are incorporated with it, 
and the same with spicules in the Rhaphidonemata &c., so 
that thé granuliferous core might be inferred to exist before 
the horny part of the fibre was supplied ; while if we examine 
the purple sponge (viz. Janthella) to which I have alluded 
in the concluding part of the preceding article—wherein 
the nucleated cells of the sarcode, taking on a pigmental 
action, become strikingly defined by their opaque deep purple 
colour rendered carmine and translucent by transmitted light 
that of two Amcebe under similar circumstances, future observation 
must determine. I have already pointed out that the “investing mem- 
brane,” or dermal sarcode, of Spongzlla, in which the pores are situated 
is thus composed (‘ Annals,’ 1857, vol. xx. p. 24, pl. i. figs. 1, 600, 6 & 7). 
